The focus of our work is on the function and regulation of genes whose expression may change with aging and/or neurodegenerative disease. We have chosen to study regulation of the amyloid precursor protein gene (APP) because of the demonstrated and suspected roles that it plays in the neuropathology and etiology of Alzheimer's Disease (AD), Down's syndrome (DS), and normal brain aging. This work is a continuation of efforts previously described under project # Z01-G00500-03: Regulation and Processing of Amyloid Precursor Protein Genes and Gene Products.) We have cloned, sequenced and characterized a portion of the rat APP gene promoter (rAPPP), and we have identified transcription start points (tsp) and important regulatory elements within this region. We are the first to describe the GAG element, which has a large positive effect in several different cell lines. A second element, designated the SAA element, appears to behave differently in different cell lines. Gel mobility shift experiments suggest that nuclear protein(s) interact directly with the SAA element but not with the GAG element. We are also investigating regulation of the D2 dopamine receptor gene (D2R) because of its demonstrated and suspected roles in the decrease in motor abilities associated with normal aging and neurodegenerative diseases such as Parkinson~s Disease (PD), schizophrenia, and tardive dyskinesia. (This project was begun as a collaboration involving 4MNU and MPGS, and was initially described under project # Z01- AG00500-03. In addition, it is a natural extension of work on the loss of D2 receptors and mRNA with aging, as discussed under project # Z01-AG00306-5: Regulation of Physiological Functions During Aging: II. Central Nervous System Responsiveness.) We have used gel mobility shift experiments to demonstrate that nuclear proteins from human HeLa cell extracts or young and old rat brain tissues will interact with DNA fragments or oligonucleotides (oligos) from this promoter region. In some cases, there appears to be greater binding activity with nuclear extracts from young liver, cerebellum, or striatum than from old liver, cerebellum, or striatum. In addition, we have contributed to the successful demonstration of the use of adenoviral vectors to express functional D2R neurotransmitter receptors in rat brain (project # Z01-AG00302-11 LCMB: Regulation of Physiological Functions III. Behavioral Biology).